U.S. Pat. No. 4,391,075 discloses an insulated roof structure wherein hangers are installed on the purlins for supporting rollers over which strips of faced glass fiber insulation are strung. Each hanger supports an axle tube and each roller includes a tubular body with bushings pressed respectively into opposite ends. The rollers have essentially the same length as the width of one of the insulation strips. Typically this is either four feet or six feet. Further, each roller has a hanger and axle tube at each end. Thus, in a typical bay between main girders, each purlin has either seven hangers supporting six four-foot rollers or five hangers supporting four six-foot rollers. At the eave struts, rollers are used to clamp the ends of the insulation strips. This has resulted in some difficulties, because raising the axle tube on one hanger raises the adjacent ends of two rollers. One of these is being moved into clamping position on a strip of insulation, but because the other is also being raised, it makes it more difficult to feed the next strip of insulation thereover.